I bought a Singer 237 Fashionmate at a garage sale. It did require cleaning, oiling, and adjusting. There is another thread about what that costs.
Then I bought a couple more of them.
The e-bay auctions say they are "industrial" - they aren't, but they are good little work horses. I can sew about four layers of denim on them before it gets cranky. I am not able to sew over a six layer bump on jean hems.
Has a beautiful straight stitch and does a nice satin stitch.
There are two versions of the 237 - one can drop the feed dogs on one model - I think that's the 237-A.
The down size of this machine - it's a heavy puppy. I think it weighs around 30 pounds. I can carry it, but not very far.